Well jet device for well testing and developing and the operating method for the well jet device

ABSTRACT

The invention relates to jet device used for extracting oil from wells. The inventive device comprises a packer, a pipe column, a jet pump, a transmitter and a receiver of physical fields. The body of the pump comprises a through stepped channel embodied in a parallel position with respect to the axes of the pipe column and having a seat disposed between steps for arranging a sealing unit, which is provided with an axial channel. Said pump body is also provided with an active nozzle. The axis of the active nozzle is disposed in a parallel position with respect to the axis of the through channel at a distance equal to or higher than 1.1 of the radius thereof. The diameter of the through channel above the seat is 0.5 mm greater than the diameter thereof below said seat. The diameter of the axial channel of the sealing unit is equal to or less than 0.6 of the external diameter thereof. The sealing unit is arranged in such a way that it is movable along a cable above a bit and successfully replaceable by the following functional inserts: a blocking insert, depression insert etc. Said inserts are provided with attachments for transporting them to the pump and extracting therefrom and for arranging instruments and samplers thereon. Said invention makes it possible to optimise the dimensions of the elements of the device and increases the reliability thereof.

FIELD OF INVENTION

This invention relates to the field of pumping engineering, mainly towell jet devices for oil production and intensification of oil inflowfrom wells.

PRIOR ART

Known in the art is a well jet device comprising a jet pump installed onthe piping string in the well and a transmitter and areceiver-transducer arranged below the jet pump (RU 2129671 C1).

From the above source known is a method of operation of a well jetdevice, which includes lowering in the well a piping string with a jetpump, a packer and a transmitter and a receiver-transducer of physicalfields, the latter being arranged below the jet pump.

The known device and method enable to explore wells and pump variousextracted media, e.g., oil, out of wells, at the same time exploring thewell, the transmitter and receiver of physical fields being arrangedwith the possibility of moving back and forth along the well relative tothe jet pump and the stratum.

But in some cases this is insufficient for obtaining reliableinformation on the well condition, which reduces the efficiency of worksperformed in order to intensify oil production.

The closest, as to its technical essence and the achievable result, tothis invention in the part of the device as the object of the inventionis a well jet device for testing and developing wells, which comprises apacker, a piping string and a jet pump, the body of the said pumpcomprising an active nozzle with a mixing chamber and having a steppedthrough passage with a mounting seat between steps for installing asealing assembly with an axial passage, the said well jet device beingprovided with an transmitter and receiver-transducer of physical fields,which is arranged on the jet pump side for entry of the medium pumpedout of the well, the output side of the jet pump is connected to thespace surrounding the piping string, the jet pump passage side for entryof the pumped out medium is connected to the inner cavity of the pipingstring below the sealing assembly, the input side of the passage forsupplying the working medium to the active nozzle is connected to theinner cavity of the piping string above the sealing assembly, and thethrough passage of the jet pump is made parallel to the axis of thepiping string (RU 2059891 C1).

The closest, as to its technical essence and the achievable result, tothis invention in the part of the method is the method of operation of awell jet device, which includes installation, on the piping string, of apacker and a jet pump, in the body of which a through passage is madewith a mounting seat, lowering of the whole assembly into the well,release of the packer and arrangement of a transmitter and areceiver-transducer of physical fields below the jet pump (RU 2121610C1).

The known well jet device and the method of operation of the well jetdevice enable to carry out various process operations in the well belowthe level at which the jet pump is installed, including those performedby lowering pressure difference above and below the sealing assembly.

But, the known well jet device and the method of operation do not enableto exploit the potential of the device in full due to non-optimalsequence of operations and dimension relations of various structuralelements of the well jet device.

DISCLOSURE OF INVENTION

The objective of this invention is to optimize the dimensions of variouscomponents of the construction of the well jet device and the sequenceof operations when carrying out works on intensifying the wellexploitation and, owing to it, to raise the efficiency of well jetdevice operation in developing and testing wells.

The stated objective in the part of the device as the object of theinvention is achieved owing to the fact that the well jet devicecomprises a packer, a piping string and a jet pump, in the body of whichan active nozzle with a mixing chamber are arranged and a steppedthrough passage is made with a mounting seat between steps forinstalling a sealing assembly having an axial channel, the said devicebeing provided with a transmitter and a receiver-transducer of physicalfields, which is arranged at the jet pump side for entry of the mediumpumped out of the well, the jet pump output side is connected to thespace around the piping string, the input side of the jet pump passagefor supplying the pumped out medium is connected to the inner cavity ofthe piping string below the sealing assembly, and the input side of thepassage for supplying the working medium to the active nozzle isconnected to the inner cavity of the piping string above the sealingassembly, and the through passage of the jet pump is made parallel tothe axis of the piping string, the axis of the active nozzle beingparallel to the axis of the through passage and being located at adistance equal at least 1.1 radii of the bigger step of the throughpassage from the latter; the diameter of the bigger step in the throughpassage, which is located above the mounting seat, is at least 0.5 mmgreater than the diameter of the step in the through passage, which islocated below the mounting seat; the sealing assembly is arranged on thewell-logging cable or on a wire fed through the axial passage andinstalled with the possibility of being replaced, e.g., in turns, by thefunctional inserts, namely, a hydrostatic testing insert, a depressioninsert, a blocking insert, an insert for recording stratum pressurerestoration curves and an insert for hydrodynamic impact on the stratum;the diameter of the axial passage in the sealing assembly is not greaterthan 0.6 outer diameter of the sealing assembly; the axes of the sealingassembly and the functional inserts are aligned with the axis of thethrough passage in the jet pump; the functional inserts are made withthe possibility of installing on them autonomous well instruments andsampling devices and are made with a tool for delivery and removal ofthem from the jet pump with the use of cable equipment, the sealingassembly being installed with the possibility of moving it along thewell-logging cable or a wire above the cap on which the transmitter andreceiver-transducer of physical fields is arranged, the latter beingconnected to the well-logging cable cap with the possibility of beingreplaced by other well instruments, e.g., a perforator, an ultrasonictransmitter, a sampling device, a thermometer, a pressure gauge, whichall may be connected, either in turns or jointly, to the well-loggingcable or a wire.

The stated objective in the part of the method as the object of theinvention is achieved owing to the fact that in the method of operationof the well jet unit includes installation on the piping string of apacker and a jet pump having a through passage with a mounting seat,lowering of that assembly into the well, release of the packer andarrangement in the well, below the jet pump, of a transmitter andreceiver-transducer of physical fields, the said transmitter andreceiver-transducer of physical fields being lowered together with asealing assembly arranged on the well-logging cable or a wire above thecap on which with the transmitter and receiver-transducer is installed,when lowering into the well, the transmitter and receiver-transducer ofphysical fields is used for background measurements of temperature andother physical fields before the well bottom, the sealing assembly isinstalled onto the mounting seat in the through passage without impedingthe back and forth motion of the well-logging cable or wire, then thetransmitter and receiver-transducer of physical fields is arranged inthe stratum interval under exploration and, by supplying the workingmedium to the nozzle of the jet pump, several values of pressuredrawdown on the stratum are successively created, and, at each itsvalue, bottom-hole pressures, compositions of the fluid coming from thestratum and the well flow rate are measured, after which the parametersof physical fields are recorded by moving the transmitter andreceiver-transducer of physical fields along the well axis in the speedrange from 0.1 to 100 meters per minute and at bottom-hole pressureschanging stepwise from the stratum pressure to 0.01 stratum pressure,the transmitter and receiver transformer of physical fields being movedalong the well axis both when the jet pump is operated and when it isshut down, then the transmitter and receiver-transducer of physicalfields is lifted out of the well, and the functional insert forrecording stratum pressure restoration curves is lowered, the saidinsert being provided with a pressure sensor and a sampling device,installed in the through passage of the jet pump, a required pressuredrawdown on the stratum is created with the use of the jet pump, and,after sharp stopping of supplying the liquid working medium to the jetpump, a stratum pressure restoration curve for the well zone under thepacker is recorded, said recording of stratum pressure restorationcurves may be done repeatedly at different pressure drawdown on thestratum; after that the results are processed, and a decision is takenwhether repair works on the well are necessary, such works beingconducted with the use of the jet pump and the alternatively appliedfunctional inserts being lowered into the well with the sealing assemblyon the well-logging cable or a wire and with, e.g., a perforator, anultrasonic transmitter, a sampling device, a thermometer and a pressuregauge, and after completion of the said works the cycle of wellexploration is repeated.

The analysis of the well jet device has shown that the reliability andefficiency of its operation may be improved both by making variouscomponents of the device under strictly defined dimensions and bycarrying out works in the well in a strictly defined succession. Duringthe operation of the device different well modes are studied. It isrequired to install and remove the sealing assembly, to move thetransmitter and receiver-transducer of physical fields along the well.It has been found that it is advisable to make the diameter of thebigger step in the through passage, which is located above the mountingseat for the sealing assembly, at least 0.5 mm greater than the diameterof the step in the through passage, which is located below the mountingseat, and the diameter of the axial passage in the sealing assemblyshould not exceed 0.6 outer diameter of the sealing assembly. In theresult, the sealing assembly is securely installed on the mounting seatand possible overflows through the sealing assembly are minimized. Thearrangement of the active nozzle axis at a distance equal at least 1.1radii of the bigger step in the through passage, when making the nozzleaxis parallel to the axis of the through passage, enables to determinethe least possible distance between the axis of the nozzle and that ofthe through passage of the jet pump and, consequently, enables todetermine the maximum permissible dimensions of the jet pump body thatis of much importance, since the diameter of the well is the mainlimiting factor when arranging equipment in the well. The possibility ofreplacing the sealing assembly with other functional inserts and thepossibility of placing, instead of the transmitter andreceiver-transducer of physical fields, other well instruments, inparticular a perforator, an ultrasonic transmitter, a sampling device, athermometer, a pressure gauge, etc., enables to conduct various works,e.g., to pressure-test the packer, transfer the well in the flow mode,conduct works on perforating the productive stratum and perform otheroperations without lifting the jet pump and the piping string from thewell. In the result, the possibilities of the well jet device inconducting studies and repair and restoration works in the well areexpanded and the time necessary for such works is shortened. Making ofinserts with the axis aligned with the axis of the through passageenables to reduce the possibility of inserts being stuck in the processof their installation or removal, which increases the reliability ofoperation of the well jet device.

Of no lesser importance is the rational organization of works aimed atexploring the well, which enable to obtain more adequate information onthe condition of the well and the productive stratum, and, due to it,accelerate the process of restoring the well output. In particular,background measurements of temperature and other physical fields in theoperation of lowering the transmitter and receiver-transducer ofphysical fields enable to get, prior to initiating inflow from thestratum, preliminary data on the present condition of the well, whichmakes it possible to elaborate practical measures for exploring the welland more adequately interpret the well exploration results in the modeof inflow from the stratum. Moving the transmitter andreceiver-transducer of physical fields along the well, especially in thearea of the productive stratum, both when the jet pump is operated orwhen it is shut down, enables to take dynamic and static characteristicsof the well. In the course of exploration it has been found thatadequate accuracy of obtained data may be obtained when moving thetransmitter and receiver-transducer of physical fields with the speedfrom 0.1 to 100 meters per minute and at changing bottom-hole pressurestepwise in the range from the normal stratum pressure to 0.01 stratumpressure. The installation of the functional inserts enables, apart fromthe above-stated possibilities, to organize different modes of welloperation, in particular, it becomes possible not only to get data onthe composition of the fluid coming from the productive stratum, butalso take important characteristics of the well, such as record astratum pressure restoration curve in the area below the packer, thispossibility being achieved due to reduction in the bottom-hole pressureup to a value being 0.01 of nominal and subsequent sharp stopping ofsupply of the liquid working medium to the nozzle of the jet pump, and,what is most important, the well jet device enables to make recordingsrepeatedly at various modes in the above-stated range. As the result,the reliability of the obtained data is significantly improved. All theabove-indicated works may be conducted without numerous re-installationsof the equipment in the well, which improves the efficiency of the welljet device greatly. After the completion of a cycle of the works onexploring and restoring the well workability, the whole cycle may berepeated, also without the necessity to re-install the equipment in thewell. Thus, the scope of investigations carried out in the well has beenexpanded, which is of importance when carrying out restoration works.

In the result, the objective of the invention—to optimize-the successionof operations and the dimensions of various components of the well jetdevice—has been achieved, and, owing to that, the efficiency ofoperation of the well jet device has been improved.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a longitudinal section of the well jet device describedherein.

FIG. 2 is a longitudinal section of the well jet device with afunctional insert installed in the through passage.

PREFERRED EMBODIMENT OF THE INVENTION

The proposed well jet device for testing and developing wells, which isserved to implement the described method, comprises the packer 1, thepiping string 2 and the jet pump 3, in the body 4 of which the activenozzle 5 with the mixing chamber 6 are axially arranged and the steppedthrough passage 7 is made with the mounting seat 8 between steps forinstalling the sealing assembly 9 having the axial channel 10, the saiddevice being provided with the transmitter and receiver-transducer ofphysical fields 11, which is arranged on the side of the jet pump 3 forentry of the medium pumped out of the well and installed on the cable 12(or a wire) fed through the axial passage 10 of the sealing assembly 9.The output side of the jet pump 3 is connected to the space around thepiping string 2, the input side of the passage 13 in the jet pump 3 forsupplying the pumped out medium is connected to the inner cavity of thepiping string 2 below the sealing assembly 9, and the input side of thepassage 14 for supplying the working medium to the active nozzle 5 isconnected to the inner cavity of the piping string 2 above the sealingassembly 9. The through passage 7 of the jet pump 3 is made parallel tothe axis of the piping string 2, the diameter D₁ of the bigger step inthe through passage 7, which is located above the mounting seat 8 is atleast 0.5 mm greater than the diameter D₂ of the step in the throughpassage 7, which is located below the mounting seat 8, the axis of theactive nozzle 5 is parallel to the axis of the through passage 7 and islocated at a distance L equal at least 1.1 radii R of the bigger step ofthe through passage 7; the sealing assembly 9 is installed with thepossibility of being replaced, e.g., in turns, by the functional inserts15, namely, a hydrostatic testing insert, a depression insert, ablocking insert an insert for recording stratum pressure restorationcurves and an insert for hydrodynamic impact on the stratum; the axes ofthe sealing assembly 9 and the functional inserts 15 are in alignmentwith the axis of the through passage 7 in the jet pump 3; the diameterD₃ of the axial passage 10 in the sealing assembly 9 is not greater than0.6 outer diameter D₄ of the sealing assembly 9; the functional inserts15 are made with the possibility of installing on them autonomous wellinstruments and sampling devices 16 and are made with a tool 17 fordelivery and removal of them from the jet pump 3 with the use of cableequipment, the sealing assembly 9 being installed with the possibilityof moving it along the well-logging cable 12 (or a wire) above theattachment cap (not shown) on which the transmitter andreceiver-transducer of physical fields 11 is arranged, the latter beingmade with the possibility of operating it in the area under the packer 1when the jet pump 3 is operated and when it is shut down and beingconnected to the cap of the well-logging cable 12 (or a wire) with thepossibility of being replaced by other well instruments, e.g., aperforator, an ultrasonic transmitter, a sampling device, a thermometer,a pressure gauge, which all may be connected, either in turns orjointly, to the well-logging cable or a wire.

The described method of operation is implemented as follows.

The jet pump 3 and the packer 1 on the piping string 2 are lowered intothe well and arranged above the productive stratum. The packer 1 is putinto the operating position (release of the packer 1), thus separatingthe space surrounding the piping string 2 in the well. The sealingassembly 9 and the transmitter and receiver-transducer of physicalfields 11 are lowered on the cable 12, the sealing assembly being putinto position on the mounting seat 8 in the through passage 7 and thetransmitter and receiver-transducer being arranged below the jet pump 3.The sealing assembly 9 separates back and forth movements of thewell-logging cable 12 or a wire. When being lowered into the well, thetransmitter and receiver-transducer of physical fields 11 is used forbackground measurements of temperature and other physical fields in thespace before the well bottom (productive stratum). Thus, the transmitterand receiver-transducer of physical fields 11 is arranged in the stratuminterval under exploration. The working medium, e.g., water, saltsolution, oil, etc., is pumped in through the piping string 2. From thepiping string 2 the working medium flows through the passage 14 to theactive nozzle 5 of the jet pump 3. Within a few seconds after pumpingthe working medium through the active nozzle 5 a stable jet is formed atthe outlet of the nozzle and, flowing out of the nozzle 5, entrains thesurrounding medium into the jet pump, which results in a pressurereduction first in the passage 13 for supplying of the pumped out mediumand then in the under-packer space of the well. In the result, thestratum medium flows to the jet pump 3 through a section of the pipingstring 2 below the sealing assembly 9 and through the passage 13, whereit is mixed with the working medium, and the medium mixture flows fromthe well to the surface through the hole clearance around the pipingstring 2 due to the energy of the working medium. During pumping outseveral values of pressure drawdown on the productive stratum aresuccessively created. At each value of the pressure drawdown thewell-bottom pressure, the composition of the fluid coming from thestratum and the well output are registered. After that the parameters ofphysical fields are recorded while moving the transmitter andreceiver-transducer of physical fields 11 along the well with the speedfrom 0.1 to 100 meters per minute and at the well-bottom pressureschanging stepwise from the normal stratum pressure to 0.01 stratumpressure. The transmitter and receiver-transducer of physical fields isthus moved both when the jet pump 3 is operated and when it is shutdown. Then the transmitter and receiver-transducer of physical fields 11is removed from the well, and the functional insert 15, which isprovided with a pressure sensor and a sampling device 16, is lowered onthe well-logging cable 12 or a wire for the purpose of recording stratumpressure restoration curves, and installed in the through passage 7 ofthe jet pump 3. With the use of the jet pump 3 a required pressuredrawdown on the stratum is created, and, after sharp stopping of supplyof the liquid working medium to the jet pump 3, a stratum pressurerestoration curve for the under-packer well space is registered.Recording of stratum pressure restoration curves may be done repeatedlyat different values of the pressure drawdown on the stratum. Then theobtained measurements are processed, and a decision may be taken whetherrepairs of the well are necessary, which are conducted with the use ofthe jet pump 3 and alternatively changed functional inserts 15 as wellwith the use of instruments lowered into the well with the sealingassembly 9 on the well-logging cable .12 (or a wire), e.g., aperforator, an ultrasonic transmitter, a sampling device, a thermometeror a pressure gauge. Depending on the performed operations, a blockinginsert, a depression insert or a hydrostatic testing insert may beinstalled on the mounting seat 8 in the through passage 7. A blockinginsert is used for closing the passages in the jet pump 3 and ensuringthe well operation in the flow mode. A depression insert is used forseparation of the piping string 2, which ensures the operation of thejet pump 3. A hydrostatic testing insert is used for pressure testing ofthe well and the packer. After completion of the above-indicated worksthe whole cycle of well exploration may be repeated, if necessary.

INDUSTRIAL APPLICABILITY

This invention may be used in testing, developing, operating andconducting work-over of oil and gas condensate wells, as well as inother industries where various media are extracted out of wells.

1. The well jet device comprising a packer, a piping string and a jetpump, in a body of which an active nozzle with a mixing chamber arearranged and a stepped through passage is made with a mounting seatbetween steps for installing a sealing assembly having an axial passage,said device being provided with a transmitter and a receiver-transducerof physical fields, which is arranged at the jet pump side for entry ofmedium pumped out of the well, the jet pump output side is connected tospace around the piping string, the input side of the jet pump passagefor supplying the pumped out medium is connected to an inner cavity ofthe piping string below the sealing assembly, and the input side of thepassage for supplying the working medium to the active nozzle isconnected to the inner cavity of the piping string above the sealingassembly, and the through passage of the jet pump is made parallel tothe axis of the piping string, characterized in that the axis of theactive nozzle is parallel to the axis of the through passage and beinglocated from the latter's axis at a distance equal to at least 1.1 radiiof the bigger step of the through passage, the diameter of the biggerstep in the through passage, which is located above the mounting seat,is at least 0.5 mm greater than the diameter of the step in the throughpassage, which is located below the mounting seat; the sealing assemblyis arranged on a well-logging cable or on a wire fed through the axialpassage and replaceable by functional inserts, including at least one ofa hydrostatic testing insert, a depression insert, a blocking insert, aninsert for recording stratum pressure restoration curves and an insertfor hydrodynamic impact on the stratum; the diameter of the axialpassage in the sealing assembly is not greater than 0.6 outer diameterof the sealing assembly; the axes of the sealing assembly and thefunctional inserts are aligned with the axis of the through passage inthe jet pump; the functional inserts are adapted for installationthereon autonomous well instruments and sampling devices and are madewith a tool for delivery and removal of the same from the jet pump withthe use of cable equipment, the sealing assembly being installedmoveably along the well-logging cable or a wire above a cap on which atransmitter and receiver-transducer of physical fields are arranged, thelatter being connected to the well-logging cable cap replaceable byother well instruments, including at least one of a perforator, anultrasonic transmitter, a sampling device, a thermometer, a pressuregauge, which all may be connected, either in turns or jointly, to thewell-logging cable or a wire.
 2. The method of operation of the well jetunit, including installation on a piping string of a packer and a jetpump having a through passage with a mounting seat, lowering of thatassembly into the well, releasing the packer and arrangement in thewell, below the jet pump, of a transmitter and receiver-transducer ofphysical fields, characterized in lowering said transmitter andreceiver-transducer of physical fields together with a sealing assemblyarranged on a well-logging cable or a wire above a cap with thetransmitter and receiver-transducer connected to the latter, whenlowering into the well, using the transmitter and receiver-transducer ofphysical fields for background measurements of temperature and otherphysical fields before the well bottom, installing the sealing assemblyonto the mounting seat in the through passage without impeding the backand forth motion of the well-logging cable or wire, then arranging thetransmitter and receiver-transducer of physical fields in a stratuminterval under exploration and, by supplying working medium to thenozzle of the jet pump, successively creating several values of pressuredrawdown on the stratum and, at each of said several values, measuringbottom-hole pressures, compositions of the fluid coming from the stratumand the well flow rate, after which, recording the parameters ofphysical fields by moving the transmitter and receiver-transducer ofphysical fields along the well axis in the speed range from 0.1 to 100meters per minute and at bottom-hole pressures changing stepwise fromthe stratum pressure to 0.01 stratum pressure, said moving beingperformed along the well axis both when the jet pump is operated andwhen it is shut down; then lifting the transmitter andreceiver-transducer of physical fields out of well, and lowering thefunctional insert for recording stratum pressure restoration providingsaid insert with a pressure sensor and a sampling device, installed inthe through passage of the jet pump, creating a required pressuredrawdown on the stratum with the use of the jet pump, and, sharplystopping of supplying the liquid working medium to the jet pump andthereafter, recording a stratum pressure restoration curve for the wellzone under the packer wherein said recording of stratum pressurerestoration curves done repeatedly at different pressure drawdown on thestratum; thereafter, processing the results and taking a decisionwhether repair works on the well are necessary, such works beingconducted with the use of the jet pump and alternatively appliedfunctional inserts being lowered into the well with the sealing assemblyon the well-logging cable or wire and including at least one of aperforator, an ultrasonic transmitter, a sampling device, a thermometerand a pressure gauge; after completion of the said works the cycle ofwell exploration is repeated.